Therefore，the in vitro bioactivity of akermanite prepared by two-step precipitation method is better than that prepared by sol一gel method.因此，两步沉淀法合成的镁黄长石相对于溶胶一凝胶法合成的镁黄长石具有更好的诱导羟基磷灰石形成能力和生物活性。

CeO 2 nanometer particles were synthesized by sol gel method,XRD analysis indicate that the systhesised CeO 2 particles are all cubic in structure,and the space group is O 5 hFm3m.用溶胶凝胶法制备了CeO2纳米粒子，XRD分析表明，所合成的CeO2纳米粒子均为立方晶系，空间群为O5hFm3m。